Anyone with unwanted yellow undertones can use a purple shampoo—and just like blondes and platinums, those with silver strands can commonly experience yellowing. “Gray hair grabs what’s in the atmosphere, so it can turn yellow very quickly,” notes Brown on an episode of Clean Beauty School, as you lose protective layers on the strands once the follicles produce less melanin and sebum.
So just as someone who lightens their hair might reach for a violet shampoo to color-correct brassy, yellow undertones, you can use the same trick to enhance your bright, gorgeous grays. “It really gives it that luminescent vibe—it feels so uplifting,” Brown adds, noting she’s been using the Olaplex No.4P Blonde Enhancer Toning Shampoo. (But you can browse all of our favorite options here, if you’re curious.)
If you’re new to the purple shampoo game, know that you can’t expect to use it like your traditional cleanser; for example, you need to let the product marinate on your strands a bit longer than normal. Feel free to follow our detailed guide here.
As for how often to use it? Sorry to say, there’s no specific schedule to follow. Everyone’s hair is different, but we recommend using it once every week or two, then building it up from there until you find your own cadence. Just know that it is possible to overdo it—especially if you have high porosity hair—which results in a (temporary!) purple tinge. “When you start using purple shampoos, you’ll know when it’s too much very quickly,” adds Brown. But don’t fret too much if you’ve tinted your hair lilac—Brown says after two or so washes all the extra pigment should fade, and you’ll be left with a beautifully cool hue.